From 6f3914d5a3269c00e70506bd95f816fef6b635ce Mon Sep 17 00:00:00 2001 From: Ulrich Drepper Date: Mon, 12 Nov 2007 23:55:58 +0000 Subject: * include/ifaddrs.c (struct in6addrinfo): Add prefixlen field. * sysdeps/unix/sysv/linux/check_pf.c (make_request): Always return list of interfaces. Also store prefix length. * sysdeps/posix/getaddrinfo.c (sort_result): Add prefixlen element. (rfc3484_sort): In rule 9, for IPv4 addresses count only matching prefix if source and destination address are in the same subnet. (getaddrinfo): Always call __check_pf. Fill in prefixlen field. Always look for matching record in in6ai list. Correct source_addr_len value for IPv6->IPv4 converted records. --- sysdeps/posix/getaddrinfo.c | 165 ++++++++++++++++++++++++-------------------- 1 file changed, 91 insertions(+), 74 deletions(-) (limited to 'sysdeps/posix/getaddrinfo.c') diff --git a/sysdeps/posix/getaddrinfo.c b/sysdeps/posix/getaddrinfo.c index 8cf9c6bdfe..57970b4363 100644 --- a/sysdeps/posix/getaddrinfo.c +++ b/sysdeps/posix/getaddrinfo.c @@ -1006,6 +1006,7 @@ struct sort_result uint8_t source_addr_len; bool got_source_addr; uint8_t source_addr_flags; + uint8_t prefixlen; }; @@ -1223,7 +1224,7 @@ static int fls (uint32_t a) { uint32_t mask; - int n = 0; + int n; for (n = 0, mask = 1 << 31; n < 32; mask >>= 1, ++n) if ((a & mask) != 0) break; @@ -1350,20 +1351,31 @@ rfc3484_sort (const void *p1, const void *p2) assert (a1->source_addr.ss_family == PF_INET); assert (a2->source_addr.ss_family == PF_INET); - struct sockaddr_in *in1_dst; - struct sockaddr_in *in1_src; - struct sockaddr_in *in2_dst; - struct sockaddr_in *in2_src; - - in1_dst = (struct sockaddr_in *) a1->dest_addr->ai_addr; - in1_src = (struct sockaddr_in *) &a1->source_addr; - in2_dst = (struct sockaddr_in *) a2->dest_addr->ai_addr; - in2_src = (struct sockaddr_in *) &a2->source_addr; - - bit1 = fls (ntohl (in1_dst->sin_addr.s_addr - ^ in1_src->sin_addr.s_addr)); - bit2 = fls (ntohl (in2_dst->sin_addr.s_addr - ^ in2_src->sin_addr.s_addr)); + /* Outside of subnets, as defined by the network masks, + common address prefixes for IPv4 addresses make no sense. + So, define a non-zero value only if source and + destination address are on the same subnet. */ + struct sockaddr_in *in1_dst + = (struct sockaddr_in *) a1->dest_addr->ai_addr; + in_addr_t in1_dst_addr = ntohl (in1_dst->sin_addr.s_addr); + struct sockaddr_in *in1_src + = (struct sockaddr_in *) &a1->source_addr; + in_addr_t in1_src_addr = ntohl (in1_src->sin_addr.s_addr); + in_addr_t netmask1 = 0xffffffffu << (32 - a1->prefixlen); + + if ((in1_src_addr & netmask1) == (in1_dst_addr & netmask1)) + bit1 = fls (in1_dst_addr ^ in1_src_addr); + + struct sockaddr_in *in2_dst + = (struct sockaddr_in *) a2->dest_addr->ai_addr; + in_addr_t in2_dst_addr = ntohl (in2_dst->sin_addr.s_addr); + struct sockaddr_in *in2_src + = (struct sockaddr_in *) &a2->source_addr; + in_addr_t in2_src_addr = ntohl (in2_src->sin_addr.s_addr); + in_addr_t netmask2 = 0xffffffffu << (32 - a2->prefixlen); + + if ((in2_src_addr & netmask2) == (in2_dst_addr & netmask2)) + bit2 = fls (in2_dst_addr ^ in2_src_addr); } else if (a1->dest_addr->ai_family == PF_INET6) { @@ -1799,63 +1811,42 @@ getaddrinfo (const char *name, const char *service, int sockfd = -1; pid_t nl_pid; #endif - /* We might need information about what kind of interfaces are available. - But even if AI_ADDRCONFIG is not used, if the user requested IPv6 - addresses we have to know whether an address is deprecated or - temporary. */ - if ((hints->ai_flags & AI_ADDRCONFIG) || hints->ai_family == PF_UNSPEC - || hints->ai_family == PF_INET6) - { - /* Determine whether we have IPv4 or IPv6 interfaces or both. We - cannot cache the results since new interfaces could be added at - any time. */ - __check_pf (&seen_ipv4, &seen_ipv6, &in6ai, &in6ailen); + /* We might need information about what interfaces are available. + Also determine whether we have IPv4 or IPv6 interfaces or both. We + cannot cache the results since new interfaces could be added at + any time. */ + __check_pf (&seen_ipv4, &seen_ipv6, &in6ai, &in6ailen); #ifdef HAVE_NETLINK_ROUTE - if (! __no_netlink_support) - { - sockfd = __socket (PF_NETLINK, SOCK_RAW, NETLINK_ROUTE); + if (! __no_netlink_support) + { + sockfd = __socket (PF_NETLINK, SOCK_RAW, NETLINK_ROUTE); - struct sockaddr_nl nladdr; - memset (&nladdr, '\0', sizeof (nladdr)); - nladdr.nl_family = AF_NETLINK; + struct sockaddr_nl nladdr; + memset (&nladdr, '\0', sizeof (nladdr)); + nladdr.nl_family = AF_NETLINK; - socklen_t addr_len = sizeof (nladdr); + socklen_t addr_len = sizeof (nladdr); - if (sockfd >= 0 - && __bind (fd, (struct sockaddr *) &nladdr, sizeof (nladdr)) == 0 - && __getsockname (sockfd, (struct sockaddr *) &nladdr, - &addr_len) == 0 - && make_request (sockfd, nladdr.nl_pid, &seen_ipv4, &seen_ipv6, - in6ai, in6ailen) == 0) - { - /* It worked. */ - nl_pid = nladdr.nl_pid; - goto got_netlink_socket; - } + if (sockfd >= 0 + && __bind (fd, (struct sockaddr *) &nladdr, sizeof (nladdr)) == 0 + && __getsockname (sockfd, (struct sockaddr *) &nladdr, + &addr_len) == 0 + && make_request (sockfd, nladdr.nl_pid, &seen_ipv4, &seen_ipv6, + in6ai, in6ailen) == 0) + { + /* It worked. */ + nl_pid = nladdr.nl_pid; + goto got_netlink_socket; + } - if (sockfd >= 0) - close_not_cancel_no_status (sockfd); + if (sockfd >= 0) + close_not_cancel_no_status (sockfd); -#if __ASSUME_NETLINK_SUPPORT == 0 - /* Remember that there is no netlink support. */ - if (errno != EMFILE && errno != ENFILE) - __no_netlink_support = 1; -#else - else - { - if (errno != EMFILE && errno != ENFILE) - sockfd = -2; - - /* We cannot determine what interfaces are available. Be - pessimistic. */ - seen_ipv4 = true; - seen_ipv6 = true; - return; - } -#endif - } -#endif + /* Remember that there is no netlink support. */ + if (errno != EMFILE && errno != ENFILE) + __no_netlink_support = 1; } +#endif #ifdef HAVE_NETLINK_ROUTE got_netlink_socket: @@ -1958,7 +1949,6 @@ getaddrinfo (const char *name, const char *service, for (i = 0, q = p; q != NULL; ++i, last = q, q = q->ai_next) { results[i].dest_addr = q; - results[i].got_source_addr = false; results[i].service_order = i; /* If we just looked up the address for a different @@ -1971,10 +1961,13 @@ getaddrinfo (const char *name, const char *service, results[i].source_addr_len = results[i - 1].source_addr_len; results[i].got_source_addr = results[i - 1].got_source_addr; results[i].source_addr_flags = results[i - 1].source_addr_flags; + results[i].prefixlen = results[i - 1].prefixlen; } else { + results[i].got_source_addr = false; results[i].source_addr_flags = 0; + results[i].prefixlen = 0; /* We overwrite the type with SOCK_DGRAM since we do not want connect() to connect to the other side. If we @@ -2005,22 +1998,39 @@ getaddrinfo (const char *name, const char *service, results[i].source_addr_len = sl; results[i].got_source_addr = true; - if (q->ai_family == AF_INET6 && in6ai != NULL) + if (in6ai != NULL) { /* See whether the source address is on the list of deprecated or temporary addresses. */ struct in6addrinfo tmp; - struct sockaddr_in6 *sin6p - = (struct sockaddr_in6 *) &results[i].source_addr; - memcpy (tmp.addr, &sin6p->sin6_addr, IN6ADDRSZ); + + if (q->ai_family == AF_INET && af == AF_INET) + { + struct sockaddr_in *sinp + = (struct sockaddr_in *) &results[i].source_addr; + tmp.addr[0] = 0; + tmp.addr[1] = 0; + tmp.addr[2] = htonl (0xffff); + tmp.addr[3] = sinp->sin_addr.s_addr; + } + else + { + struct sockaddr_in6 *sin6p + = (struct sockaddr_in6 *) &results[i].source_addr; + memcpy (tmp.addr, &sin6p->sin6_addr, IN6ADDRSZ); + } struct in6addrinfo *found = bsearch (&tmp, in6ai, in6ailen, sizeof (*in6ai), in6aicmp); if (found != NULL) - results[i].source_addr_flags = found->flags; + { + results[i].source_addr_flags = found->flags; + results[i].prefixlen = found->prefixlen; + } } - else if (q->ai_family == AF_INET && af == AF_INET6) + + if (q->ai_family == AF_INET && af == AF_INET6) { /* We have to convert the address. The socket is IPv6 and the request is for IPv4. */ @@ -2029,10 +2039,17 @@ getaddrinfo (const char *name, const char *service, struct sockaddr_in *sin = (struct sockaddr_in *) &results[i].source_addr; assert (IN6_IS_ADDR_V4MAPPED (sin6->sin6_addr.s6_addr32)); + sin->sin_family = AF_INET; + /* We do not have to initialize sin_port since this + fields has the same position and size in the IPv6 + structure. */ + assert (offsetof (struct sockaddr_in, sin_port) + == offsetof (struct sockaddr_in6, sin6_port)); + assert (sizeof (sin->sin_port) + == sizeof (sin6->sin6_port)); memcpy (&sin->sin_addr, &sin6->sin6_addr.s6_addr32[3], INADDRSZ); - results[i].source_addr_len = INADDRSZ; - sin->sin_family = AF_INET; + results[i].source_addr_len = sizeof (struct sockaddr_in); } } else if (errno == EAFNOSUPPORT && af == AF_INET6 -- cgit 1.4.1